This invention relates to a multiple cylinder internal combustion engine of the fuel injection type and more particularly to an improved induction system for such an engine.
The advantages of manifold fuel injection as a means for charge forming with internal combustion engines is well known. Basically such fuel injection gives better fuel flow control over a wide speed range. The relatively high cost of injection nozzles and the necessity for providing a separate nozzle for each cylinder or chamber of the engine has, however, deterred wider acceptance of their usage.
It is, therefore, a principal object of this invention to provide an improved induction system for an internal combustion engine in which the simplified fuel injection arrangement may be incorporated.
Although it has been proposed, with engines having conventional induction systems, to employ one fuel injection nozzle for a plurality of cylinders, this arrangement is not completely satisfactory. Due to pulsating and irregular flow patterns through conventional intake manifolds, such arrangements have resulted in unequal mixture distribution between the various cylinders served by a single fuel injection nozzle. Furthermore, when one injection nozzle is provided for multiple cylinders it must be positioned in a common passage of the induction system which serves the cylinders. Thus, the injection nozzle will be spaced a considerable distance from the cylinders which it serves. Because of this spacial difference, engine performance during transitional stages (acceleration and deceleration) will be deteriorated.
It is, therefore, a further object of this invention to provide an improved induction system in which one fuel injection nozzle may serve a number of chambers without variations in mixture strength.
Another reason why the provision of one fuel injection nozzle for a plurality of cylinders has not proven completely satisfactory is the difficulty in providing an injection system which is capable of providing the full load and speed range fuel requirements of a plurality of cylinders with a single injection nozzle. As should be readily apparent, at high engine speeds the single injection nozzle must discharge at a greater number of cycles per minute. Thus, it has been previously necessary to employ very expensive fuel injection systems even though only one nozzle is employed for a plurality of chambers.
It is, therefore, a yet further object of this invention to provide a fuel injection system for an internal combustion engine in which one nozzle serves a number of chambers and yet is capable of providing accurate fuel control even at high engine speeds.